Advanced energy storage promises to play a key role in modernizing our nation’s electricity grid to enable the integration of increasing amounts of renewables, improve operating capabilities, enhance reliability, allow deferral of infrastructure investments and provide backup power during emergencies. While batteries may soon provide short-duration energy storage at reasonable costs, they do not perform as well for longer durations, for example multi-day storage. One alternative is power-to-gas technologies, such as water electrolyzers that convert electricity to chemical energy in hydrogen (H2), which can then be stored in pressurized tanks. These approaches provide excellent longer-term storage at a lower cost, but suffer from poor roundtrip efficiencies relative to electrical energy storage in batteries.
Project Innovation + Advantages:
The team led by Pajarito Powder will develop a reversible hydrogen electrode that would enable cost-effective hydrogen production and reversible fuel cells. Both electrolyzers and fuel cells, generally operate in acidic conditions that rely on expensive precious metal catalysts to avoid corrosion. Running the electrochemical cell in alkaline conditions reduces the requirements for the oxygen electrode, but effective and inexpensive electrocatalysts for the hydrogen electrode still need to be developed. This project aims to develop a bi-functional (i.e. two way) low-cost catalyst that runs in alkaline conditions capable of oxidizing or reducing hydrogen depending on whether power is needed immediately, or needs to be stored. By integrating the electrolyzer and fuel cell into one system, the overall cost could be drastically reduced, which would open an entire suite of new applications including grid load-leveling and long-term energy storage applications. The system will be compatible with intermittent energy sources because it can operate at lower temperatures than competiting technologies, thus allowing startup times on the order of seconds.
If successful, this technology could yield greatly improved water electrolyzers, which could enable low-cost energy storage compatible with intermittent renewable energy sources, such as solar and wind power.
Storing energy from intermittent renewables over long durations in a cost-effective manner could reduce demand on the electric grid, while produced H2 or derived liquids could provide a low-carbon alternative to fossil fuels for transportation.
Clean energy storage technologies could allow high penetration of emissions-free renewable power.
The team’s innovations could reduce the cost of long-term energy storage and therefore enable renewables to be more cost competitive with conventional generation sources.